Studies on malate formation in isolated guard cells
Travis, A.J.; Mansfield, T.A.
New Phytologist 78(3): 541-546
ISSN/ISBN: 0028-646X DOI: 10.1111/j.1469-8137.1977.tb02157.x
After they were isolated by a low pH tretament which destroyed all other cells of the epidermis, stomatal guard cells retained the capacity to produce malate when presented with fusicoccin as a stimulus to opening. For a given level of stomatal opening, the amount of malate in epidermis with isolated stomata was practically the same as in intact epidermis. Malate transport to and from the subsidiary cells was not an essential part of the stomatal mechanism. Changes in CO2 concentration over the range 0-100 ppm did not affect stomatal aperture or malate levels in epidermis of Commelina communis. Carboxylation of phosphenolpyruvate may play no major part in the formation of malate in guard cells.